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E N J O Y T H E G E N U I N E 1. DNA molecule imaged by AFM. - PDF document

Enter the Gift code at www.ntmdt.com and get a www.ntmdt.com and get a present from NT-MDT Co. present from NT-MDT Co. Attention: limited quantity! Attention: limited quantity! Be in time to get your gift! Be in time to get your gift! E N J


  1. Enter the Gift code at www.ntmdt.com and get a www.ntmdt.com and get a present from NT-MDT Co. present from NT-MDT Co. Attention: limited quantity! Attention: limited quantity! Be in time to get your gift! Be in time to get your gift! E N J O Y T H E G E N U I N E 1. DNA molecule imaged by AFM. Uncoiled regions are marked by arrows. 2. Live cell image by AFM in physiological conditions. Two points of surface differ in stiffness. 3. Bundle of carbon nanotubes imaged by tip-enhanced Raman microscopy.

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  3. Oral Presentation, Theme G : Nano-Optics, Nano-Optoelectronics, Nano-Photonics Nano-photonic wire waveguides Hamza Kurt, 1 * ������������������� 2 and Kadir Üstün 1 1 Department of Electrical and Electronics Engineering, TOBB University of Economics and Technology, Ankara 06560, Turkey 2 Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara 06531, Turkey Abstract- We study the light propagation in nano-photonic wire silicon waveguides with right angle corners. The low transmission efficiency of 55% can be increased up to 99% by careful manipulation of the corner area. The study yields compact size structures and it may assist the implementation of optical interconnects to distribute effectively optical clock signals through the chip. The dielectric waveguides are commonly occupied in First, the addition of two rods improves the bending efficiency photonic integrated circuits because compact and low-loss up to 80%. On top of that, the second improvement comes waveguide structures are the ingredient component of diverse from the location search of one rod which is shown as dotted photonic applications ranging from dense wavelength division line in the figure. The transmission coefficient increases as the multiplexing devices to optical interconnects in the H-tree rod is shifted toward the corner region. The efficiency branches [1]. The high density integration requires reduction increases as the shift amount increases and reaches of the device dimensions towards micro-meter to even nano- monotonically up to 99% value within the normalized meter domain. To fulfill this demand, photonic wire frequency range of 0.30-0.36. It can be concluded from the waveguide concept has been exploited by implementing the analysis that the parameter tuning of position of the rod and width of the structure in the sub-micron region [2-3]. The low addition of two rods dramatically change the transmission loss nature of straight waveguide under the absence of efficiency. scattering and leakage losses is disturbed by the inherit necessity of sharp corners which is an essential part to distribute optical signal through any location on the chip. Due to the huge bending losses, small bending angles should be implemented. High-index dielectric contrast confines light strongly in the core section of the waveguide. However, the similar high-loss due to sharp corners in photonic wires makes the engineering of junction area a mandatory task. In this work, by integrating photonic wire waveguide Figure 2. The time snap shots of continuous pulse propagation for a corner region with photonic crystals we inhibit the light regular photonic wire right angle bend in left and same source escaping mechanism by means of photonic band gap propagation for the optimum structure designed in the present work confinement. There is no cavity type modification at the in right. To verify the high transmission through the 90 0 corner region. As a result of this, the solution is broadband. bend in real-time, we study a continuous wave propagation in Fig. 2. The time snap shot of the movie confirms the almost perfect transmission without any radiation losses that occurs in the absence of PC. When there is no PC around the right angle region, huge amount of light escapes by coupling into radiation mode. However, the bending loss is negligible with the implementation of the proposed design in the present work. In conclusion, the huge bend losses of nano-photonic wire Figure 1. The figure demonstrates a regular photonic wire waveguide waveguide are replaced by the wideband transmission surrounded by photonic crystal at the corner region. The width of the efficiency of approximately 99% which is achieved by dielectric slab is 0.20 a and the relative permittivity of the material is embedding photonic crystal structure with appropriate 12. parameters around the corner area. The study may facilitate The photonic wire structure consists of a Si-core the design of Si-based nano-photonic waveguide branches for surrounded with air cladding. The ( 1 � 3 . 45 ) ( 2 � 1 . 0 ) n n future optical interconnects that may eventually lead to optical waveguide width was selected considering single mode clock distribution by means of H-tree waveguide operation. Relying on the huge advancement in the configuration. manufacturing capability of the sub-wavelength dimensional This work was partially supported by TUBITAK under devices with CMOS technology, we selected the width of Grant No. TBAG-108T717. waveguide to be approximately 100 nm. Such values will be *Corresponding author: hkurt@etu.edu.tr ultimately required when higher levels of integration are targeted [3]. Fig. 1 shows the manipulations performed in the [1] L. Pavesi and G. Guillot, Optical Interconnects: The Silicon proposed structures. We inserted two additional rods and fixed Approach, Springer, 2006. their locations. Another rod of the same radius is moved along [2] C. Manolatou, et. al., J. Lightwave Technol. 17, 1682- the diagonal direction. The amount of applied shift for the rod 1692 (1999). � . The improvement on the [3] G. T. Reed, Nature 427, 595–596 (2004). location is traced by symbol x [4] S. K. Selvaraja, et. al., J. Lightwave Technol. 27, 4076-4083 transmission efficiency depends on the two step modifications. (2010). 133 6th Nanoscience and Nanotechnology Conference, �zmir, 2010

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